1. Field of the Invention
The invention relates to preparation of aqueous detergent slurries with reduced viscosity. This invention also relates to preparation of a particulate detergent and the novel detergent composition.
Particulate detergent compositions are generally prepared by forming an aqueous slurry of the materials which form the detergent and drying the slurry. The slurry of the detergent forming composition is generally formed in a apparatus called a crutcher. Since the water present in the slurry must be removed to form a particulate detergent, the slurry generally has as low a concentration of water as permitted by the required handling of the slurry in the drying operation.
Detergent compositions generally comprise at least one surfactant, detergent builders such as phosphates, maleic acid/vinyl ether copolymers, silicates, carbonates, salts of nitrilotriacetic acid, zeolites and the like, fillers such as sodium sulfate, sodium chloride and various additives which prevent redeposition, brighten the clothes, chelate metal ions and the like.
2. Statement of Related Art
It is known that the inclusion of a small amount of alkyl glycosides and particularly alkyl polyglycosides in phosphate built detergent slurry compositions, reduces the slurry viscosity so that a higher concentration of the non-aqueous ingredients can be included in the slurry. U.S. Pat. No. 4,675,127, which is incorporated herein by reference, discloses phosphate built detergent compositions containing small amounts of alkyl polyglycosides to reduce the viscosity of the slurry and permit inclusion of a higher concentration of the non-aqueous ingredients in the slurry. U.S. Pat. No. 4,536,319 which is incorporated herein by reference discloses detergent compositions containing alkyl polyglycoside surfactant and a co-surfactant.
With the advent of environmental concerns, many locales have banned the use of phosphates in detergent compositions or severely limited the amount of phosphate which can be present. One of the detergent builders which has been substituted for the now banned phosphates is sodium carbonate. The inclusion of alkyl polyglycosides alone in a carbonate built detergent composition, does not have the effect of substantially reducing the viscosity of the slurry. Accordingly, slurries containing higher proportions of water are required so that the detergent slurry can be handled and transported to the drying apparatus. The inclusion of the additional water in the detergent slurry reduces the capacity of the drying apparatus and increases the cost of preparing the particulate detergent composition.